(1) Field of the Invention
This invention relates to a couple of connectors for use as automobile wiring harnesses, or the like, and more particularly to a couple of connectors with an engagement checking structure having means for detecting a completely engaged state of a connector couple.
(2) Prior Art
Referring to FIGS. 5 and 6, A designates a male connector housing, B designates a female connector housing, and each of them is formed of synthetic resin materials.
In the male connector housing A, a plurality of terminal receiving cavities 1 are formed, as is well known, and female terminal pieces C are inserted to be secured therein.
Similarly, in the female connector housing B, a plurality of terminal receiving cavities (not illustrated in the drawings) are formed, and male terminal pieces D are inserted to be secured therein.
In a concave portion 2 of an upper surface of the male connector housing A, a cantilever resilient lock arm 3 with a vertical base member 3a is provided as extending afterward. On an upper surface of a middle part of the resilient lock arm 3, a lock projection 3b is formed, and on a free end of the resilient lock arm 3, a push portion 3c for unlocking is provided. In a center portion of a forward end of a top wall 4, in regard to the female connector housing B, an engaging frame 5 corresponding to the resilient lock arm 3 is provided, and a lock opening 5a corresponding to the lock projection 3b is also formed on the top wall 4.
The aforementioned structure is well known art wherein, when the male connector housing A and the female connector housings B engage with each other, the female terminal pieces C and the male terminal pieces D make contact with each other. At that time, the lock projection 3b abuts the engaging frame 5, whereby the resilient lock arm 3 deflects downwardly into a lower space R provided for allowing a deflection of the resilient lock arm 3 and, thereafter, the lock projection 3b reaches to the lock opening 5a. As the resilient lock arm 3 returns to the original position, the male connector housing A and the female connector housing B are completely engaged with each other and locked thereby.
Numeral 6 denotes a contact piece for detecting engagement. The contact piece 6 has a pair of elastic contact portions 6b/6b which rise up from a folded corner 6' at one end of a base plate 6a and has, at the other end of the base plate 6a, a terminal nose piece 6c being folded oppositely to the elastic contact portion 6b. The terminal nose piece 6c has a tab which extends afterward from a folded corner 6" thereof. A pair of contact pieces 6/6 for detecting engagement are secured by engaging the folded corner 6' thereof with an end of a compartment wall between the concave portion 2 and the terminal receiving cavity 1' adjacent to the concave portion 2. Thereby, a couple of the elastic contact portions 6b/6b rise up in the space R for allowing a deflection, opposing the free end of the resilient lock arm 3. And the terminal nose pieces 6c/6c with the tab are oppositely secured in the respective terminal-receiving cavities 1'/1' The terminal nose pieces 6c/6c with the tab are connected with the normal female terminal pieces C. An electric detection circuit is composed thereby.
Numeral 7 designates a short-circuit contact member which is formed of an elastic metal and is gate-shaped. The legs 7a/7a of the short-circuit contact member 7 each have an outwardly folded contact piece 7b. The short-circuit contact member 7, wherein the folded contact pieces 7b/7b are engaged by an associated strip 5b on the engaging frame 5, is fixed to the engaging frame 5 by an adhesive, or the like.
In the above-mentioned structure, when the male connector housing A and the female connector housing B are incompletely engaged with each other, the free end of the resilient lock arm 3, as illustrated in FIG. 6B, deflects downwardly and also forces the elastic contact portions 6b/6b of the contact pieces 6/6 to deflect for detecting engagement. Therefore, as the short-circuit contact member 7 is isolated from the elastic contact portions 6b/6b, the detecting electric circuit does not operate.
On the other hand, when the male connector housing A and the female connector housing B are completely engaged to each other, the resilient lock arm 3, as illustrated in FIG. 6C, returns to its original position and also the elastic contact portions 6b/6b of the contact pieces 6/6 for detecting engagement return to their original position. Thereby, the elastic contact portions 6b/6b make contact with the short-circuit contact member 7 and the detecting electric circuit operates.
In the above-mentioned prior art, the male connector housing with the resilient lock arm 3 has a couple of the contact pieces for detecting engagement, and the female connector housing has the short-circuit contact member. Further, the male connector housing A has a couple of female terminal pieces, which, when engagement between the terminal pieces and the housing is complete, are connected to the contact pieces 6 to detect the complete engagement. Consequently, the described engagement checking structure is so complicated that more compact ones have been sought.